> -----Original Message----- > From: Thomas Monjalon [mailto:[email protected]] > Sent: Wednesday, November 30, 2016 10:27 AM > To: Ananyev, Konstantin <[email protected]> > Cc: Harish Patil <[email protected]>; [email protected]; Rahul Lakkireddy > <[email protected]>; Stephen Hurd > <[email protected]>; Jan Medala <[email protected]>; Jakub > Palider <[email protected]>; John Daley <[email protected]>; Adrien > Mazarguil <[email protected]>; Alejandro Lucero > <[email protected]>; Rasesh Mody > <[email protected]>; Jacob, Jerin <[email protected]>; > Yuanhan Liu <[email protected]>; Yong Wang > <[email protected]>; Kulasek, TomaszX > <[email protected]>; [email protected] > Subject: Re: [dpdk-dev] [PATCH v12 0/6] add Tx preparation > > 2016-11-30 17:42, Ananyev, Konstantin: > > > >Please, we need a comment for each driver saying > > > >"it is OK, we do not need any checksum preparation for TSO" > > > >or > > > >"yes we have to implement tx_prepare or TSO will not work in this > mode" > > > > > > > > > > qede PMD doesn’t currently support TSO yet, it only supports Tx > TCP/UDP/IP > > > csum offloads. > > > So Tx preparation isn’t applicable. So as of now - > > > "it is OK, we do not need any checksum preparation for TSO" > > > > Thanks for the answer. > > Though please note that it not only for TSO. > > Oh yes, sorry, my wording was incorrect. > We need to know if any checksum preparation is needed prior > offloading its final computation to the hardware or driver. > So the question applies to TSO and simple checksum offload. > > We are still waiting answers for > bnxt, cxgbe, ena, nfp, thunderx, virtio and vmxnet3.
The case for a virtual device is a little bit more complicated as packets offloaded from a virtual device can eventually be delivered to another virtual NIC or different physical NICs that have different offload requirements. In ESX, the hypervisor will enforce that the packets offloaded will be something that the hardware expects. The contract for vmxnet3 is that the guest needs to fill in pseudo header checksum for both l4 checksum only and TSO + l4 checksum offload cases. > > This is for any TX offload for which the upper layer SW would have > > to modify the contents of the packet. > > Though as I can see for qede neither PKT_TX_IP_CKSUM or > PKT_TX_TCP_CKSUM > > exhibits any extra requirements for the user. > > Is that correct?
